Ribbon和Feign 服务构建区别

feign和ribbon是Spring
Cloud的Netflix中提供的两个实现软负载均衡的组件，Ribbon和Feign都是用于调用其他服务的，方式不同。Feign则是在Ribbon的基础上进行了一次改进，采用接口的方式。

pom文件

<!--ribbon-->
    <!-- https://mvnrepository.com/artifact/org.springframework.cloud/spring-cloud-starter-ribbon -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-ribbon</artifactId>
        <version>1.4.7.RELEASE</version>
    </dependency>
     <!--feign-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
            <version>1.4.7.RELEASE</version>
        </dependency>
          <!--eureka-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>

1.启动类使用的注解不同，Ribbon 用的是@RibbonClient，Feign 用的是@EnableFeignClients

@SpringBootApplication
@EnableEurekaClient
@RibbonClient(name = "SPRINGCLOUD-PRIOVIDER-DEPT", configuration = myRule.class)

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients(basePackages = {
    
    "com.gjf.springcloud"})

2.服务的指定位置不同，Ribbon 是在@RibbonClient 注解上声明，Feign 则是在定义抽象方法的接口中使用@FeignClient 声明

@Configuration
public class ConfigBean {
    
    

    //配置负载均衡实现RestTemplate
    //IRule
   // RoundRobinRule 轮询
    //RetryRule 先按照轮询获取服务，失败，则在指定时间重式
    @Bean
    @LoadBalanced //Ribbon开启负载均衡的功能
    public RestTemplate getRestTemplate() {
    
    
        return new RestTemplate();  }}

@Component
@FeignClient(value = "SPRINGCLOUD-PRIOVIDER-DEPT")
public interface DeptClientService {
    
    
    @PostMapping("/dept/add")
    public boolean addDept(Dept dept);

    @GetMapping("/dept/get/{id}")
    public Dept queryById(@PathVariable("id")Long id);

    @GetMapping("/dept/all")
    public List<Dept> queryAll();
}

3.调用方式不同，Ribbon 需要自己构建 http 请求，模拟 http 请求然后使用 RestTemplate 发送给其他服务，步骤相当繁琐。

Ribbon 创建RestTemplate

@RestController
public class DeptConsumerController {
    
    
    //消费者无service层
    @Autowired
    private RestTemplate restTemplate;
   // private static final String REST_URL_PREFIX = "http://localhost:8001";
    //Ribbon地址是个变量
   private static final String REST_URL_PREFIX = "http://SPRINGCLOUD-PRIOVIDER-DEPT";
    @RequestMapping("/consumer/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id) {
    
    
        return restTemplate.getForObject(REST_URL_PREFIX + "/dept/get/" + id, Dept.class);
    }
    @RequestMapping("/consumer/dept/add")
    public boolean add(Dept dept) {
    
    
        return restTemplate.postForObject(REST_URL_PREFIX + "/dept/add", dept, Boolean.class);
    }
    @RequestMapping("/consumer/dept/all")
    public List<Dept> deptList() {
    
    
        return restTemplate.getForObject(REST_URL_PREFIX + "/dept/all", List.class);
    }
}

Feign使用抽象方法的接口注入

 @Autowired
    private DeptClientService deptClientService;

@Component
@FeignClient(value = "SPRINGCLOUD-PRIOVIDER-DEPT")
public interface DeptClientService {
    
    
    @PostMapping("/dept/add")
    public boolean addDept(Dept dept);

    @GetMapping("/dept/get/{id}")
    public Dept queryById(@PathVariable("id")Long id);

    @GetMapping("/dept/all")
    public List<Dept> queryAll();
}

@RestController
public class DeptConsumerController {
    
    
    //消费者无service层
    @Autowired
    private RestTemplate restTemplate;
    // private static final String REST_URL_PREFIX = "http://localhost:8001";
    //Ribbon地址是个变量
    /* private static final String REST_URL_PREFIX = "http://SPRINGCLOUD-PRIOVIDER-DEPT";*/
    @Autowired
    private DeptClientService deptClientService;

    @RequestMapping("/consumer/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id) {
    
    
       /* return restTemplate.getForObject(REST_URL_PREFIX + "/dept/get/" + id, Dept.class);*/
        return this.deptClientService.queryById(id);
    }

    @RequestMapping("/consumer/dept/add")
    public boolean add(Dept dept) {
    
    
      /*  return restTemplate.postForObject(REST_URL_PREFIX + "/dept/add", dept, Boolean.class);*/
        return deptClientService.addDept(dept);
    }

    @RequestMapping("/consumer/dept/all")
    public List<Dept> deptList() {
    
    
        /*return restTemplate.getForObject(REST_URL_PREFIX + "/dept/all", List.class);*/
        return deptClientService.queryAll();
    }
}